Abstract: In order to satisfy the adaptability of counterrecoil mechanism of cased telescoped ammunition gun to different ammunitions, a magneto-rheoligical fliud (MRF) damper based on multistage annular channel is proposed, which can satisfy the maximum recoil force and reduce the recoil displacement. The magnetic circuit of magneto-rheological energy absorbers (MREA) is analyzed by using the finite element method, and the relationship between the exciting current and the average magnetic induction intensity in the damping channel is obtained. The model parameters of MR fluid under non- and magnetic fields are identified based on the experimental data obtained by an Anton Paar rheometer. The flow differential equations of MR fluid in the buffering channel are established in considering the inertia effect and the boundary slip. The flow velocity distribution of MR fluid is obtained, and the relationship between piston speed and buffering force of damper is deduced. A MREA is fabricated based on the theoretical analysis above, and a drop hammer impact test bench is set up. Impact tests at different impact speeds are carried out, and the experimental data are compared with the theoretically analyzed results. Results show that the velocity distribution characteristics of magnetorheological fluid are similar under the conditions of different inertia effects and slippage boundary, but the peak value of velocity varies. When the boundary slippage coefficient is 0.000 1, the theoretical buffering force of MRF damper is close to the experimental value. Under the impact velocity of 1.55 m/s, the peak value of buffering force is increased by 15 000 N when the current increases from 0 A to 3 A. Under the impact velocity of 1.90 m/s, the peak value of buffering force is increased by 25 000 N when the current increases from 0 A to 4 A.Key

Key words: gun, recoilmechanism, magnetorheologicalfluid, damper, slipboundary, inertialeffect